Stary Voltage

Status
Not open for further replies.
I don't really have a problem but I was wondering if I could hear some of your explanations for stray voltage when doing an above ground pool and you have to explain to the customer about the bonding and stray voltage. I had this guy a while back and boy oh boy ,I nearly had to break out the text books because he wanted to play a game of 20 questons .
 

jbelectric777

Senior Member
Location
NJ/PA
The bonding requirements of article 680 NEC is to create whats called an equipotential ground. Sounds Latin to most but what it means is they want the area of the pool to be able to sense ANY potential current including from neighbors faults and trip the GFCI protecting the people using the pool. Thats why we bond or connect (bond means to connect and make common) all conductive (metal) parts and/or equipment within 5 feet of the pool, all the pumping and heatind/circulating equipment that is conductive, pipes, diving board rig, cups and sometimes even aluminum siding/windows, fences and the list goes on. The intent is not to sink a ground rod or connect an EG over and above Art:680 but to be able to sense a ground fault in the area of the pool and trip the GFCI. Note that 2008 code requires all pumps no matter where they are located to be GFCI. Its the best protection for swimmers in my opinion.
 

kwired

Electron manager
Location
NE Nebraska
The bonding requirements of article 680 NEC is to create whats called an equipotential ground. Sounds Latin to most but what it means is they want the area of the pool to be able to sense ANY potential current including from neighbors faults and trip the GFCI protecting the people using the pool. Thats why we bond or connect (bond means to connect and make common) all conductive (metal) parts and/or equipment within 5 feet of the pool, all the pumping and heatind/circulating equipment that is conductive, pipes, diving board rig, cups and sometimes even aluminum siding/windows, fences and the list goes on. The intent is not to sink a ground rod or connect an EG over and above Art:680 but to be able to sense a ground fault in the area of the pool and trip the GFCI. Note that 2008 code requires all pumps no matter where they are located to be GFCI. Its the best protection for swimmers in my opinion.

Having everything bonded together will likely help with causing a GFCI to trip because with less resistance fault current will flow easier.

But I don't think that is why you build an equipotential plane, the idea is to minimize the potential voltage between adjacent conductive items.

There could be hundreds or even thousands of amps flowing through the conductive items and at any voltage level but if they are all the same potential there is no risk of shock when you contact more than one of them at the same time, to receive a shock you must contact different voltage potentials.
 

mcclary's electrical

Senior Member
Location
VA
Having everything bonded together will likely help with causing a GFCI to trip because with less resistance fault current will flow easier.

But I don't think that is why you build an equipotential plane, the idea is to minimize the potential voltage between adjacent conductive items.

There could be hundreds or even thousands of amps flowing through the conductive items and at any voltage level but if they are all the same potential there is no risk of shock when you contact more than one of them at the same time, to receive a shock you must contact different voltage potentials.

I agree, post #2 is not accurate, the equipotential bonding grid is not required to be extended to a panel board, therefor, it DOES facilitate the opening any over current device. It is there to do exactly what it is named,,,,keep every thing at an EQUAL POTENTIAL
 

kwired

Electron manager
Location
NE Nebraska
...they want the area of the pool to be able to sense ANY potential current including from neighbors faults and trip the GFCI protecting the people using the pool...

A GFCI will not respond to current on an equipment grounding conductor or grounding electrode conductor that did not originate from a conductor that is fed through the GFCI.

You can have a thousand amps flowing through your grounding system, if it did not originate from the load side conductors of the GFCI protected circuit the GFCI will not even see a microamp of it.
 
Status
Not open for further replies.
Top